1. Field of Invention
The present invention relates to locking and unlocking mechanisms and more particularly, to apparatus for remotely releasing lock mechanisms.
2. Description of the Invention Background
In certain types of sterilizers and washers, a loading car carrying items to be sterilized or cleaned can be rolled directly into the chamber of the sterilizer/washer on tracks designed specifically to guide the loading car. Loading cars of this type are typically mounted on a transfer carriage which has wheels and can be pushed from place to place to bring the items to be sterilized or cleaned, including the loading car, to the sterilizer/washer and to return the loading car full of clean or sterilized items to a desired destination.
A loading car can also be unloaded from a sterilizer/washer on to a transfer platform contained in a sealed, airtight environment such as an isolator workstation. One of the walls or the floor of these sealed workstations usually has a worksuit that is formed into the upper torso of a human being, including work gloves. This configuration allows items on the transfer platform to be manipulated in the airtight environment. Examples of known isolator workstations that may contain a transfer carriage and have a worksuit are disclosed in Amsco publication Nos. SD-446 and SD-448, copies of which are filed concurrently herewith.
Often, however, it is difficult to safely transfer the loading car between the transfer carriage and the chamber of the sterilizer/washer. Many sterilizer/washers have a gap of from several inches to a foot between the chamber opening and the front panel of the sterilizer/washer. The transfer carriage cannot be pushed beyond the lower front panel. To permit the loading car to traverse the gap between the lower front panel and the chamber opening, conventional transfer carriages have extended track sections which meet the track within the sterilizer/washer chamber so that the loading car can roll along the track extensions into to rout of the chamber. The operator pushes the loading car into the chamber or pulls it out of the chamber over the extended tracks. The full weight of the loading car full of goods is borne by the extended tracks. There is a danger that the weight of the loading car will tip the extended tracks and the transfer carriage and thereby cause the transfer carriage to tip or roll back. The loading car can then crash to the ground.
Another problem is in the poor alignment that sometimes occurs between the extended tracks of the transfer carriage and the chamber tracks. If the tracks of the transfer carriage are not properly aligned with the tracks of the chamber, the loading car will not ride smoothly into the chamber, but will run into the side of the track or end frame of the chamber when the operator pushes the car forward. Often, the operator cannot see clearly whether the tracks are aligned when pushing the car from behind.
When unloading a loading car onto the transfer carriage, the operator must pull the loading car from the hot sterilizer/washer. Some systems do not have the loading cars locked into place. If these tracks are slightly tilted because the sterilizer is not level, the loading car can roll out of the chamber when the door is opened. If the loading car is somehow restrained in the chamber, the operator must reach into the hot chamber to release the loading car before removing it from the sterilizer/washer, then pull the car out over the track extensions onto the transfer carriage. Furthermore, the transfer carriage itself is on wheels and thus, can roll away from the sterilizer/washer while the operator is pulling or pushing the loading car.
When unloading a car from the sterilizer/washer onto a transfer platform contained in a workstation, the operator is prevented by the walls and the worksuit of the workstation from reaching into the sterilizer/washer. Therefore, it is very difficult for an operator in the workstation to reach into the chamber to unlock the loading car and then reset the locking mechanism. Furthermore, the opening of the sterilizer/washer is very hot after a sterilization cycle, and this heat would damage the working gloves of the worksuit if the operator had to contact the sterilizer/washer opening to release a loading car.
There is a need for a mechanism to secure the transfer carriage in position relative to the sterilizer/washer for safe transfer of the loading car into and out of the chamber. There is a further need to lock the loading car into the chamber and to remotely unlock the loading car to eliminate the need for operators to reach into hot sterilizer/washers to release the car. There is a further need to unlock the loading car in the chamber and reset the locking mechanism remotely from an isolator workstation. Finally, there is a need for a fail safe mechanism to prevent release of the loading car until the transfer carriage is securely positioned relative to the sterilizer/washer.